Waste FOG Biodiesel Coupling Process for Catalyst-Stable Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing biodiesel production processes using waste FOG as raw material face instability due to high impurity content, leading to catalyst inactivation and reduced efficiency, and existing technologies primarily use refined vegetable oils, competing with food resources and lacking stability in long-term operation.
Innovation Solution
A coupling process involving pre-esterification, hydrogenation, deep deoxygenation, and hydroisomerization steps with catalyst recycling, including a suspended-bed reactor to remove impurities and a fixed-bed reactor for stable operation, using ionic liquid catalysts and ionic liquid catalysts supported on graphitized mesoporous carbon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If waste FOG is used as raw material in existing hydrodeoxygenation processes, then biodiesel production can be achieved, but the system becomes unstable and catalyst inactivates due to high impurity content
Solution Approach 1:
The patent applies preliminary action by implementing a pre-esterification step before the main hydrodeoxygenation process. This pre-treatment converts free fatty acids in the waste FOG into esters, removing harmful impurities that would otherwise cause catalyst inactivation. The pre-esterification reaction occurs in a separate reactor with acid catalyst, and the treated oil is then fed to the hydrodeoxygenation unit, ensuring stable long-term operation.
Solution Approach 2:
The patent segments the biodiesel production process into distinct stages: pre-esterification, hydrodeoxygenation, and hydroisomerization. Each stage is performed in separate reactors with specific catalysts and conditions optimized for that step. This segmentation allows impurities to be removed progressively, preventing catalyst poisoning in the main reaction units while maintaining high biodiesel yield.
2Reliability
If hydroisomerization is performed during hydrodeoxygenation, then cetane number is improved, but low-temperature flow performance deteriorates due to branched alkane formation
Solution Approach 1:
The patent applies parameter changes by carefully controlling the hydroisomerization conditions, including temperature, pressure, and catalyst composition. By optimizing these parameters, the process achieves high cetane number through controlled branching while minimizing excessive isomerization that would harm low-temperature flow. The specific catalyst formulation and reaction conditions are tuned to balance these competing requirements.
3Ease of manufacture
If first-generation biodiesel is produced through transesterification, then production is simple, but application value is limited due to poor stability and low-temperature fluidity
Solution Approach 1:
The patent applies continuity of useful action by extending the simple transesterification process with additional treatment steps that maintain continuous production flow. The pre-esterification, hydrodeoxygenation, and hydroisomerization steps are integrated in sequence, creating a continuous process that transforms low-value waste FOG into high-value second-generation biodiesel without interrupting production, thereby improving both fuel quality and economic viability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Achieves a stable and efficient production of second-generation biodiesel with high alkane yield and isoparaffin content, overcoming catalyst inactivation and impurity issues, enabling long-term system operation and high yield of biodiesel.
Implementation Method 1
charging the filtrate and a certain amount of a short-chain alcohol and a liquid acid catalyst into a pre-esterification reactor for a pre-esterification reaction to generate a pre-esterified mixture
Implementation Method 2
charging the pre-esterified mixture into a liquid-liquid separator for liquid-liquid separation to separate out an aqueous phase and an organic phase
Implementation Method 3
pre-hydrogenating the esterification product II, an oil-soluble hydrogenation catalyst, a vulcanizator, and hydrogen gas in a suspended-bed reactor to generate a product I
Implementation Method 4
mixing the oil phase product I and hydrogen gas, charging the mixture into a fixed-bed reactor for a deep deoxygenation reaction to obtain a mixed product I
Implementation Method 5
mixing the oil phase product II and hydrogen gas, and charging the mixture into a hydroisomerization reactor for an isomerization reaction under an action of a catalyst, to generate a product II
Implementation Method 6
charging the liquid phase product into a fractionation tower to separate out isomerized biodiesel and an aviation fuel product
Implementation Method 7
charging the dissolved waste FOG into a filter to remove solid impurities
Implementation Method 8
charging the pre-esterification product I into a water scrubber to remove metal ions to obtain an esterification product II
Data Source
AI summary
A coupling process for producing biodiesel from a waste FOG including: among others, 1) removing solid impurities from a waste FOG, then mixing with an alcohol and liquid acid catalyst to generate a pre-esterified mixture; 2) mixing the mixture with water, and charging the mixture to separate an aqueous phase to remove metal ions to obtain an esterification product II; 3) mixing the product II with a vulcanizator and H2 to generate a product I; 4) and separating the product I to obtain an oil phase, mixing the oil phase with H2 and passing the mixture into a fixed-bed reactor, and using a gas-liquid separator for separation to obtain an oil phase product II.